|
|
Design of a chamber for storing metal powders
Jeleček, Petr ; Červinek, Ondřej (referee) ; Koutný, Daniel (advisor)
Additive manufacturing from metallic materials is a continously evolving branch of the engineering industry, where correct material storage is a crucial aspect. The main objective of this bachelor’s thesis is to create a structural design of a chamber for storing barrels containing metal powders. A survey of commercially available storage systems highlighted a gap in the market, specifically of fully or partialy automated storage systems that could also be used in a laboratory environment. The conceptual designs are inspired by commercially available storage systems and include a new, unconventional solution. After the evaluation of conceptual designs a specific structural design was developed that met the project criteria. The final design enables storing barrels containing metal powders in an inert atmosphere and partialy automates the transport of barrels between the storage and the work space.
|
|
| |
|
|
Influence of Inert Atmosphere on Surface Wetting in Lead Free Soldering
Nestrojil, Michal ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This master´s thesis dealing with study of influence of inert atmosphere on the wettability of soldered surfaces. The theoretical part is discussed the issue of the soldering, solder joint, oxidation, and inert atmosphere. The glass cover with internal inert gas preheating for the wetting balance testing was prepared in the practical part. With this adjustment were realised tests, in which was examined the effect of the inert gases on the wettability of different materials combination. Further experiments were focused on plasma surface cleaning as possible flux substitution. The evaluation of these experiments were discussed in the end of this master´s thesis. Some of topics were designed for further experiments.
|
|
|
Special Laboratory Techniques
Boháčová, Zdeňka ; Merna,, Jan (referee) ; Richtera, Lukáš (advisor)
Manipulation with the materials that are very sensitive towards moisture and (or) oxygen requires controlled environment with acceptable content of these undesired species in the range of ppm units. The knowledge of vacuum techniques, techniques of the dry box and Schlenk techniques is necessary in the area of inorganic, organic, and especially organometallic and polymer syntheses. General procedures that are related to these techniques are described in many lecture notes and monographs, but the graphic form which can enhance correct understanding, is often very poor. The thesis is divided into eight chapters, beginning with laboratory safety, risk assessment and the first aid. Following chapter brings useful literature sources. Used glassware, laboratory equipment and accessories and special techniques are described in other chapters. The aim of this work was to create the study materials which could be utilized by the workers dealing with the syntheses of organometallic complexes, catalytic precursors for polymerization and polymerization in itself in the laboratory of polymer synthesis at the Faculty of Chemistry, BUT.
|
|
|
Passivation of the active layer in perovskite solar cells with inverted architecture
Babincová, Kristina ; Zmeškal, Oldřich (referee) ; Pospíšil, Jan (advisor)
The topic of this work is the passivation of the active layer of perovskite solar cells with an inverted structure. The work is divided into theoretical and experimental part. The theoretical part describes in particular the passivation and modification of the perovskite layer as well as the characteristic properties of perovskite, including structure and stability. The experimental part deals with the preparation of photovoltaic cells with an inverted structure. For the characterization of photovoltaic cells, reference samples were prepared and their active layer was modified by plasma. The most used deposition technique for the preparation of layers was the spin coating method. From the performed experiments it can be concluded that the preparation of samples and their subsequent modification under laboratory conditions does not lead to the improvement of the final parameters of photovoltaic conversion. By transferring the sample preparation and passivation of the active layer to an inert atmosphere, it was possible to produce cells with higher efficiencies (compared to the reference sample), around 10 %. Another advantage of this plasma treatment of the active layer is that it also improves the stability of the prepared structures, which even after a few days in air show almost 80 % of the original efficiency.
|
|
|
Design of storage containers for powdered metal materials
Vaverka, Ondřej ; Koukal, Ondřej (referee) ; Koutný, Daniel (advisor)
This bachelor’s thesis deals with design of storage container for powdered metal materials used in 3D printer. It contains a short overview of possibilities in metal powders storage, SLM workplace’s requirements and analysis of this problem. Based on this, the goals are specified. The work deals with various solutions and their assessments. In the last part the final version is described, including neccessary calculations and drawings.
|
|
|
Passivation of the active layer in perovskite solar cells with inverted architecture
Babincová, Kristina ; Zmeškal, Oldřich (referee) ; Pospíšil, Jan (advisor)
The topic of this work is the passivation of the active layer of perovskite solar cells with an inverted structure. The work is divided into theoretical and experimental part. The theoretical part describes in particular the passivation and modification of the perovskite layer as well as the characteristic properties of perovskite, including structure and stability. The experimental part deals with the preparation of photovoltaic cells with an inverted structure. For the characterization of photovoltaic cells, reference samples were prepared and their active layer was modified by plasma. The most used deposition technique for the preparation of layers was the spin coating method. From the performed experiments it can be concluded that the preparation of samples and their subsequent modification under laboratory conditions does not lead to the improvement of the final parameters of photovoltaic conversion. By transferring the sample preparation and passivation of the active layer to an inert atmosphere, it was possible to produce cells with higher efficiencies (compared to the reference sample), around 10 %. Another advantage of this plasma treatment of the active layer is that it also improves the stability of the prepared structures, which even after a few days in air show almost 80 % of the original efficiency.
|
|
| |
|
|
Influence of Inert Atmosphere on Surface Wetting in Lead Free Soldering
Nestrojil, Michal ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This master´s thesis dealing with study of influence of inert atmosphere on the wettability of soldered surfaces. The theoretical part is discussed the issue of the soldering, solder joint, oxidation, and inert atmosphere. The glass cover with internal inert gas preheating for the wetting balance testing was prepared in the practical part. With this adjustment were realised tests, in which was examined the effect of the inert gases on the wettability of different materials combination. Further experiments were focused on plasma surface cleaning as possible flux substitution. The evaluation of these experiments were discussed in the end of this master´s thesis. Some of topics were designed for further experiments.
|
|
|
Design of storage containers for powdered metal materials
Vaverka, Ondřej ; Koukal, Ondřej (referee) ; Koutný, Daniel (advisor)
This bachelor’s thesis deals with design of storage container for powdered metal materials used in 3D printer. It contains a short overview of possibilities in metal powders storage, SLM workplace’s requirements and analysis of this problem. Based on this, the goals are specified. The work deals with various solutions and their assessments. In the last part the final version is described, including neccessary calculations and drawings.
|
guest ::
